Gauge



June 16, 1931. c i. JoHANssoN 1,810,710-

Y GAUGE original Filed Apm 12, 1925 Patented June 16, 1.931

PATENT OFFICE CARL EDVARD JOHANSSON, F DETROIT, MICHIGAN GAUGE Original application- The present invention relates to an improvement in gauges. of the kind Vwhichconsist of a head or similar body' secured to a suitable handle, and in which there are provided a fixed or adjustable measuring stud and a sliding measuring stud located in alignment with the first-named stud, said two studs being adapted during the measuring to be placed in contact with the objects tobe measured, and which gauges are provided with two pointers one of which servesv for the preliminary or rough measurement, for instance during the first stages of the working, and is actuated by the sliding measuring stud, and the other of which serves for the accurate vmeasurement and is actuated through a gear mechanism so that it gives a greater deviation than the first-named pointer for the same movement of the measuring stud. This application is a division of my copending application Serial No. 631,499, led April 12:, 1923, which issued Dec. 24, 1929 as Patent No. 1,740,695. The object of the invention is to provide agauge of this kind which shall have small dimensions and yet possess a large measuring range and which simultaneously renders possible very accurate measurements within a certain portion of said masuring range where particularly great accuracy is desired.- For thisl purpose the invention consists broadly in that. the gear mechanism is so constructed that the accurate measurement pointer moves only when the pointer actuated by the sliding measuring stud moves in the vicinity on both sides of the zero point on a scale for said pointer, but is released and will therefore be at rest during the other movement of the rough measurement pointer. In this manner it is possible to use a comparatively short scale and thus to obtain smalll dimensions of the gauge, and in addition the important advantagbJ is also attained. that, for instance when measuring a piece of work in the course of its manufacture, the .accurate measurement pointer will begin to move only when the rough measurement .pointer approaches thefcorrect measure and thus indicates to the machinist that the piece'of work approaches the correct measure, so that greater caution in Figs. l and 2.

iled April 12, 1923, Serial No. 631,499, and in Sweden April 27, 1922. Divided and "this application led'i'February 8, 1928. Serial No. 252,700.

must be observed during the rest of the operation.

The present invention also contemplates a i further improvement'of the indicating device for the purpose of makinoP possible a simpler and less expensive manufacture of the same and to render is possible to make the gauge of such shape that its range of usefulness will be increased. For this purpose the two pointers are pivoted on a common axis and are actuated by a lever inserted between said4 pointers' and the sliding measuring stud, the Ione short arm of said lever being actuated by the measuring stud, and different lengths of the other longer arm of said lever actuating the two pointers in such manner that one of said vpointers performs a greater movement than the/,other pointer for the same movement of the'y measuring stud. By this insertion of a lever between themeasuring stud and thel two pointers it is possible to make the narrow portion of the gauge nearest to the measuring stud of a sufficient length -fer making it possible to measure also long holes of small diameter, and the serviceableness of the` gauge 'is thus increased.

The accompanying drawings illustrate by i way of example two embodiments of the invention. Fig. 1 shows a gauge for measuring internal dimensions constructed according to the invention, inside elevation and in section through the head on the common axis l of the two measuring studs, and Fig. 2 shows a longitudinal section of the gauge. Fig. 3 shows a side elevation, partly in section, of a second embodiment, of which Fig. 4 shows a longitudinal section. Fig. 5 is a fragmentary view showing a modification of the embodiment illustrated in Fig. 3 adapted for measuring external dimensions. Fig. 6 is an end elevation ofthe gauge shown The gauge illustrated in Figs. 1 and 2 has a frame or housing consisting of a head 1 which is secured to a hollow shaft 2 the portion ofwhich adjacent the head 1 is formed as a box 3 coveredby transparent cover 53,

said box containing a gear mechanism and j two pointers with corresponding scales. In the head 1 there are provided an adjustable measuring stud 4, a sliding measuring stud 5 and two sliding, locating studs 6l The adjustable measuring stud 4 is screw-threaded into the head and may be locked in its position after adjustment for instance by means of a set screw 7,. The movable measuring stud 5 slides freely with its inner thick part in a bore in the head 1, while its outer portion which is of a slightly smallerdiameter, slides in the bushing 8 which is screwthreaded into the head and which simultaneously serves to prevent the measuring stud from dropping out of the head. Against the inner plane end of the measuring stud the knife-shape extension 9 of a pivoted arm bears. Said arm carries a pointer Y10 and is pivoted on the screw 11 which is threaded into the bottom of the box 3, and the pointer is actuated by a spring 12 which maintains the edge 9 bearing against the inner end sur face of the measuring stud 5. The spring 12 tends to turn the pointer 10 to bear against a stop 13 projecting from the bottom of the box. A pressure inwards on the measur ing study 5 will move the pointer 10 away from said stop until its movement is finally checked by a stop screw 14 screw-threaded into the side wall of the box 3.

On the side of the fulcru'm 11 opposite the edge 9 the pointer arm is provided with a second edge 15 directed in the opposite direction, by means of which edge the pointer acl tuates a second pointer 16 of slightly shorter length. Said pointer 16 is pivoted on a pin 1-7 in a bearing 18 which is secured by means of a screw 19 to the bottom of the box 3 and which may be adjusted in proper position by means of two set screws 20. A coil spring 21 maintains the pointer 16 in engagement with the edge 15 and tends to turn the pointer against the stop 13. The edge 15 engages the pointer 16 in a plane Vthrough the point of the pointer and its axis of rotation 17. free and left to itself the spring 12 determines the position of said measuring stud as well as the positions of the two pointers 10 and 16, the spring 12 being stronger than the spring 21, so that the edge 15 on the pointer 10 moves aside the pointer 16.

T he two pointers 10 and 16 move over separate portions 'of a scale 22 which is provided with two zero points, one for each pointer. The gear mechanism between the two pointters is so dimensioned, in the embodiment illustrated, that when the pointer 10 points to the zero point on the lower half provided for the same of the scale 22 in Fig. 1, the pointer 16 also points to the Zero point on the upper portion provided for the same of the scale, and that for the same movement of the measuring stud 5 the point of the pointer 16 moves through ten times the distance covered by the point of the pointer 10, so that if, for instance, the movement of the pointer When the measuring stud 5 is- 10 from one line to the next on the lower half of the scale represents a movement of the measuring stud 5 of 0.1 mm., the movement of the pointer 16 from one line to the next on the upper half of the scale represents a movement of the measuring stud 5 of 0.01 mm. The pointer 10 will therefore be used for rough measuring, whereas the pointer 16 will be used for the inal accurate measure. In accordance herewith the pointer 16 takes partin the movement only when the pointer 10 moves between the two lines on each side nearest to the zero point on the lower half of the scale, whereas during the movement of the pointer 10 over the remaining portion of the lower half of the scale the pointer 16 is at rest bearing against the stop 13. By this arrangement of two pointers cooperating in the manner above described the essential advantage is attained that with a comparatively short scale and short pointers and consequently small dimensions of the box 3 it is possible to take rough measures within a large measuring range, for instance during the first stage of the working, and also accurate measurements with very great accuracy within that portion of the measuring range of the gauge where the greatest accuracy is required, that is to say in the immediate vicinity of the correct measureI which is attained when both pointers point to their respective zero points.

In certain cases it may be desirable to be able to lock the pointer 10 in any position on the scale 22, and in order to render this possible there is'provided a locking device in the tubular shaft 2 of the gauge. Said device consists of a piston 27 movable in the cylindrical cavity of the shaft 2 and actuated by a coil spring 26. To said piston 27 a rod 28 is secured eccentrically, said rod extending behind the bottom of the box 3 to a flat spring 29 secured at one end to said bottom. Said spring 29 is provided at its other end with a portion 30 bent approximately at right angles to the spring yand projecting into an opening in the bottom of the box 3, in the vicinity of the screw 1l. When the piston 27 is allowed to move to the left iu Fig. 2A under the actuation of its spring 26, the end of the rod 28 actuates the spring 29 and forces the portion 30 of the saine through the opening in the bottom of the box and against the pointer 10 which is thus 'forced against the head of -the.screw 11.

against the action of the spring 26 by slightf ly turning said piston 27 so that the neck of a button 31 secured to the piston and projecting through an angular slot 32 .in the lao wall of the shaft'2, is moved into the portion of said slot 32 which is perpendicular tothe longitudinal direction of the shaft 2. If it is desired, while measuring, to fix the position of the pointer 10 on the scale 22, it is only required to turn the piston 27 so that the button 31 moves out of the said portion of the slot 32, after which the spring 26 moves the piston 27 to the left in Fig. 2, so that the rod 28 forces the portion 30 of the spring 29 against the pointer 10 withthe result that said pointer" 10 and thus also the pointer 16 are locked positions.

When the gauge described is to be used for measuring it is {irst introduced into a snap gauge formed or built up of standard measuring blocks and shanks or into a standard ring of the ydesired exact dimension. The adjustable measuring stud 4 is now turned until both pointers 10 and 16 point to their rein their respective spective zero points, after which thel measuring stud 4 is locked in itsposition thus determined. By means of the gauge adjusted in this manner it is afterwards possible tp observe the making of a hole or a slot in 'a piece of work, while said piece is secured in the machine, fromthe time when about 2 mm. remain until the attaining of the desired measure, and when the machining-.has been finished it is possible to ascertain whether the diameter ofl the holeor the width of the slot is exactly equal to the standard meas- 'f both measuring studs 4 and 5 should be on let the same diameter so that the correct dimension will be obtained. Such locating of the gauge in the correct position is considerably facilitated by the two locating studs 6, which are secured to a sliding plate 47 located ina recess 48 in the head 1 and covered by a cover-f' 49 secured to the head by screws 50. Said plate is pressed outwardly by two strong coil springs 51, located in boxes 52 in said plate and pressing against the bottoms of said bores and against the upper wall of said recess 48, thus tending to move the studs 6 in a downward direction, as shown in Fig. 6, so that their outer ends will bear against the wall of the hole and thus center the instrument.

In the embodiment above described the box 3 is arranged in such manner that its center line is perpendicular to the common axis of the two measuring studs. Such arrangement, however, is not necessary, as it is of course also possible, if desired or suitable for anyv special purpose, to arrange the box more or less obliquely to said axis.

The gauge illustrated in Figs. 3 and 1s also provided with an adjustable measuring `stud 4 and a sliding measuring stud 5 which are located in alignment, thelatter in the body 1- and the former in-an arm 33 projecting from said body, and also with two pointers 10 and 16 which are movable over different portions of the scale 22, and the former of which is used for rough measuring and the latter of which serves for the final accurate measuring. Both pointers are rotatable on a common pivot 34 secured in the body 1, and each pointer is actuated by a flat spring 35 and 36 respectively which tend to move the pointers against a stop pin 37. According to the invention there is inserted 'a lever 38 between 'the sliding stud 5 and the two pointers, 'said lever being pivoted on a screw 39 secured in the body 1, and the short arm of the lever being'actuated by the measuring stud 5 while the long arm of the lever actuates the two pointers.

In order to render possible adjustment of the ratio between the movements of the measuring stud and the pointers the lever is provided at both ends with slides 40 and 41 which are movable in longitudinal slots 23 and 24 respectively in the lever and may be secured in adjusted positions by means of screws 42 and 43. The slide 40 at the end of the short arm of the lever carries an edge 44 which bears against a plane shoulder on the measuring stud 5, so that when the measuring stud slides the lever 38 will be turned. The slide 41 at the end of t-he long arm of the lever carries in similar manner an edge 45 which bears against a planesurface on the accurate measurement pointer 16. The rough measurement pointer 1 0, on the other han-d, bears with an edge 46 directly against the' lever 38. By adjusting the slide 40 it is thus possible to adjust the ratio between the movements of the measuring stud 5 and the rough measurement pointer l10, and by adjustment of the slide 41 it is possible to adjust the rz1- tio -between the movements of the two pointers. y g As in the first embodiment the pointers 10 and '16 move over different portions of the scale 22 which is also in this embodiment provided with two zero points, one for each pointer. vThe gearing between the `two pointers is arranged in such mannerthat when the pointer 10 points to the zero point on the upper portion of the scale, .the pointer 16 also .points to the zero point of the lower half of the scale, and t-he gearing may be so adjusted inthe manner above described that for the -same movement of the measuring stud 5 the scale, whereas' during the movement of the pointer l() overthe remaining portion of the upper half of the scale, that is-to say before the accurate measuring is to begin, the pointer 16 is at rest and bears against the stop pin 37. This pin also prevents the pointer 1() from moving more than one line below the upper zero point on the scale. During the rough measuring, when only the pointer 10 moves, the measuring pressure is determined by the tension of the spring 35, but during the accurate measuring, when both pointers move, the measuring pressure is determined by the difference between the tensions of the two springs 35 and 36. The spring 35 must therefore be stronger than the spring 36.

The gauge is primarily intended to be used for measuring internal dimensions, for instance the diameter' of a hole. By the insertion of the lever 38 between the measuring stud 5 and the two pointers the advantage above referred to is attained that the gauge may be used for measuring also long or deep holes of small diameter. The gauge may easily be changed, however, in such, manner that it will also be serviceable for external measurements. Fig. 5 illustrates a modification of the gauge shown in Fig. 3 adapted for external measurements. This embodiment differs from the one illustrated in Fig. 3 only in that the arm 33a which supports the measuring stud 4, is located on the same side of the body l as that on which the sliding measuring stud 5 projects. The stud l is thus directed towards the stud 5, so that the object to be measured, may be introduced between said studs. In other respects this gauge is' constructed similarly to that shown in Fig. 3, and similar reference numerals are used to denote similarparts. As regards the indications on the scale it is to be noted that in respect of internal measures the lines between the two Zero points of the scale denote minus or under-size allowances, whereas in respect of external measures said lines denote plus or over-size allowances.,` f

I claim:

1. In a gauge the combination of a head, two measuring studs located in alignment in said head and adapted to engage Walls on the object to be measured, one of said studs being adapted to slide in said head, a pointer actuated by said sliding stud, two locating studs located in said head on either side of and at equal distances from said sliding measuring stud and disposed in a plane conimon to said measuring studs, means for rigidly securing said locating studs to one another, said locating studs and connecting means being movable in said head in a direction parallel to the direction of movement of said sliding measuring stud, and means urging said locating studs in a direction outwardly of said head.

2. In a gauge the combination of a head,

vtwo measuring studs located in alignment ink said head, and adapted to engage walls on the object to be measured, one of said studs being adapted to slide in said head, a pointer actuated by said sliding stud, a slide slidable in said head in a direction parallel to the direction of movement of said sliding measuring stud, means acting on said slide to urge the same outwardly of said head and two 1ocating studs rigidly secured to said slide and located on either side of and at equal distances from said sliding measuring stud, and disposed in a .plane common to said measuring studs.

3. In a gauge, the combination of a housing comprising a head, two measuring studs carried in alignment by said head, one of said studs being slidable inwardly thereof, an indicator pivotally mounted in said housing and actuated by said sliding stud, two rigidly connected movable locating studs carried by said head in a plane common to said measuring studs and adapted to move in a direction parallel to the direction of movement of said sliding measuring stud, means for positioning said locating studs one on either side of and equidistant from said sliding measuring stud, a spring urging said sliding measuring stud outwardly of said head, and at least one spring similarly actuating said locating studs, said last-mentioned spring exerting a pressure considerably in excess of that of said first mentioned spring.

4. In a gauge the combination of a frame having a head, two measuring studs carried in alignmentby said head, one of said studs being slidable inwardly thereof, a pointer pivotally mounted in said frame and actuated by said sliding stud, a slide slidable in said frame in a direction parallel to the direction of movement of said sliding measuring stud, tw'o locating studs rigidly secured to said slide, and normally projecting from said head, said locating studs being positioned one on either side of and equidistant from said sliding measuring stud, a spring urging said sliding measuring stud outwardly of said head, and at least one spring acting on said slide to similarly actuate said locating studs, said last-mentioned spring exerting a pressure considerably in excess of that of said first-mentioned spring.

5. In a gauge the combination of a frame, two measuring studs located in alignment in said frame, one of said studs being slidable in said frame, a pointer actuated by said sliding stud, two rigidly connected locating members adapted to move in a direction parallel to that of said sliding measuring stud, means for positioning said locating members one on either side of'and equidistant` from said sliding measuring stud, said measuring studs and said locating members having their operative ends located in the same plane, a spring actuating said sliding measaoV uring stud, and at least one spring actuating said locatmg members, said last-mentloned sprmg exerting a pressure conslderably in excess of that of said lfirst-mentioned means carried by said head and guided thereby in a direction parallel to the direction of movement of said sliding measuring stud,`a

' spring acting on said guided means for movlng the same also away from said stationary stud, and a pair of locating elements on said guided means and movable therewith, said locating elements being positioned one on each side of and equi-distant from said m0v` able measuring stud and being disposed in a plane common to said measuring stud.

In testimony whereof, I have subscribed my name. Y

CARL EDYARD OHANSSON.

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